1. Field of the Invention
The present invention relates generally to measuring objects and more particularly to improved systems for measuring internal parameters of a cavity.
2. Description of the Related Art
In many different fields, and particularly in aerospace engineering, various parameters for items are measured to ensure that the items, when manufactured, meet design specifications. These design specifications are specified as parameters needed for the item to perform properly. Design specifications may include, for example, dimensions, weight, and composition. The parameters may have tolerances within which the different parameters should fall.
For example, with a newly manufactured wing, a number of parameters for the wing should be within specified tolerances. In other words, the parameters should not vary beyond whatever range that is specified for a particular tolerance. These parameters include dimensions for different parts of the wing, such as the height, straightness, angle, and spacing of cavities and internal surface of cavities within the wing. These parameters are measured to ensure that the wing will perform properly and safely once the wing is mounted to an airplane. If, for example, the newly manufactured wing does not meet desired tolerances, then the wing is modified to ensure compliance with the desired tolerances or the wing will be discarded in favor of a new wing that does meet desired tolerances.
Some items are designed to have internal cavities. For some of these items, the parameters of the internal cavities are measured to ensure that these parameters meet desired tolerances. For example, many types of aircraft wings have internal cavities that have specified dimensions.
Measuring an internal cavity within an object, such as a wing, may be challenging. Currently, in some cases, the different pieces of the wing may be measured before these pieces are put together. In other cases, the wing is formed in one piece with the cavities. In this case, the parameters of the internal cavities can be measured only by taking apart the wing. However, this solution is undesirable because taking apart the wing makes the wing unusable.
Thus, currently, a prototype aircraft wing is constructed, opened, and then measured. If the tolerances for the prototype wing are met, then production wings are made to fill orders. Purchasers have to trust that these subsequently manufactured aircraft wings have the same desired tolerances.
However, trusting that an aircraft wing meets desired tolerances usually is unacceptable because of the strong desire to produce safe aircraft. Furthermore, aircraft wings are expensive and time-consuming to manufacture. Therefore, it would be advantageous to have an improved method and apparatus to measure the internal parameters of a cavity within an object.